Selective call receivers, including pagers, typically alert a user of a received message by producing an audio alerting signal. However, the audio signal may be disruptive in various environments, and therefore, vibrators have been utilized to provide a "silent" alerting signal.
Referring to FIG. 1, a conventional vibrator motor 100 comprises a cylindrical body 102, a longitudinal, rotating shaft 104, and an unbalanced, rotating counterweight 106. The cylindrical body 102 is held in place on a printed circuit board 108 by motor bracket 110. The counterweight 106 is attached to the protruding end of the shaft 104 on the vibrator motor 100. Operationally, the motor 100 is energized by a power source causing the shaft 104 and the counterweight 106 to rotate, resulting in the motor 100 vibrating and, consequently, the selective call receiver vibrating, thereby alerting the user.
With the trend to miniaturization, the vibrator motor has become one of the largest components in silent alert type pagers. It is, therefore, difficult to realize further reductions in the size of a silent alert pager unless the vibrator motor itself is reduced in size. However, it is important that the vibration level not be significantly reduced, since it would defeat the advantage of size reduction if the tactile operation was ineffective.
Thus, what is needed is a miniaturized vibrator suitable for use in a selective call receiver for generating a tactile alert.